66741281609 has 2 divisors, whose sum is σ = 66741281610. Its totient is φ = 66741281608.

The previous prime is 66741281599. The next prime is 66741281611. The reversal of 66741281609 is 90618214766.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 60754855225 + 5986426384 = 246485^2 + 77372^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66741281609 is a prime.

It is a Sophie Germain prime.

Together with 66741281611, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (66741281809) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33370640804 + 33370640805.

It is an arithmetic number, because the mean of its divisors is an integer number (33370640805).

Almost surely, 2^66741281609 is an apocalyptic number.

It is an amenable number.

66741281609 is a deficient number, since it is larger than the sum of its proper divisors (1).

66741281609 is an equidigital number, since it uses as much as digits as its factorization.

66741281609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 870912, while the sum is 50.

The spelling of 66741281609 in words is "sixty-six billion, seven hundred forty-one million, two hundred eighty-one thousand, six hundred nine".